The bundling communication method allows making use of a plurality of communication links simultaneously for the purpose of improving data transference rates. In order to be efficient, cost effective and reliable, the bundling mechanism should fill certain requirements. First, it needs to support both constant bit rate (CBR) services (e.g. voice traffic over time division multiplexing (TDM) channels, Video streams) and statistical traffic which includes data frames. The end-to-end delay should be as low as possible: less then 5 ms for CBR traffic, and less then 10 ms for statistical traffic. In addition, the end-to-end jitter should be as low as possible, especially for the CBR whose jitter should amount to practically zero. Static traffic may endure up to 10 ms of jitter. The sequential order of the traffic is also very important; traffic generated on the far side needs to be in keeping with the received order.
The bundling mechanism should also be scalable. It should support bundling using varying numbers of links, from as little as 8 links and up to 128 links. The bundling cost should be proportional to the number of used links. Furthermore, the bundling mechanism should operate using links with different bit rates simultaneously (from 256 kbit/s and up to 8 mbit/s); the bundled links may be symmetrical or asymmetrical.
The bundling mechanism should support bit error rate (BER) measurements and reports, in order to enable redirection of the transmitted traffic over the bundled links according to the receive side BER (per link), within 50 ms. Whenever the BER of one of the links crosses a predefined threshold, it is removed from the bundle within 50 ms. The link is added back to the bundle once its BER drops back beneath the threshold. The switching of a link should be performed without affecting the traffic.
Finally, the bundling mechanism should support independent transmission and reception paths, in order to ensure that at any given moment, links only in use in one direction.
Known in the art are several methods for establishing a communication route using bundling methods. The MultiLink Point to Point Protocol (MLPPP) is a method of splitting, recombining, and sequencing datagrams across multiple logical data links. Its mechanism which operates without fragmentation transmits each frame over a separate link. The main shortcoming of this method is that it causes high delay and high jitter. Using the same mechanism with fragmentation is not scalable. In addition, it is not equipped to handle CBR data.
The inverse multiplexing on ATM (IMA) is a physical layer technology, in which a high-speed stream of asynchronous transfer mode (ATM) cells is broken up and transmitted across multiple T1/E1 links, then it is reconstructed back into the original ATM cell order at the destination. It has similar shortcomings as the MLPPP mechanism. It has relatively high overhead costs, may only operate with multiple links which have the same bit rate, and it is not scalable.
There is therefore a need for a system and a method which could provide a scalable, carrier class bundling multiplexed data communication to be implemented on low rate links. The system and the method need to overcome the limitations of prior art while complying with the data transference specifications of both CBR and statistical traffic.